Temperature control for engine cooling systems



July 19, 1949. T. B. DILWORTH TEMPERATURE CONTROL FOR ENGINE COOLING SYSTEMS Filed Jan. 29, 1947 ISrmentor v Patented July 19, 1949 2 UNITED STATES AT E'Nfr eerie E,

Mich, .a corporation of Delaware Application January 29, 1941, SeriaINoQYZS M'ZZ 4 Claims. (01. 1 23-4 78 The present invention relates to engine "coolin systems of the temperature responsive type.

The principal object of the present invention is to provide a simple cooling system for an en-- gine including an engine radiator, a radiator shutter and cooling fan and means responsive to the temperature of the engine for controlling overlapping reversed sequential operation of the radiator :shutter and fan to maintain more uniform engine temperature for wide variations in ambient temperature, and engine speed, load and output.

The combined engine coolingsystem by which the above and other objects are accomplished will become apparent by reference to the following detailed description and drawing illustrating one modification of "my coolin system which is particularly adapted for locomotives. V

Figure '1 is a cross sectional elevation of the portion of a locomotive including the engine and cooling system therefor.

Figure '21s a wiring'diag-ram showing the temperature responsive control apparatus in schematiciiorm.

Figure 3 is an enlarged cross sectional view of a detail shown 'inFigure '1.

As .best'fillustratedfin Figure 1 ahood I mounted .on the underframe 3 of a locomotive is provided with a cooling air inlet opening in one end .and a baffle .1 is shown extending inwardly and diagonally upwardly from the lower edge of the .air inlet opening to the rear of .an air outlet opening '9 in the top of the hood to provide an upper compartment in which an engine coolant radiator ll and cooling fan .13 are mounted and a lower compartment for thefloeomoti e engine [5 of the internal combustion type and fan driving means mounted on the underirame .3. Shut? ter blades ll pivoted about vertical axes in the hood I are provided in .the air inlet Opening 5 thereof. An air pressure cylinder [.9 having va well known type of .electromagnetically operated pressure application and relief shutter control valve 121 connected thereto in a well known :mannor for controlling pressure application to and relief of pressure irom the cylinder L9 in order tolcause the opening of the shutter blades l1 upon energization of the valve winding 21' shown in Figure :2. The piston-and rod'of the cylinder to mhown connected-to operating arms 23 of the shutter blades H to move the blades to the open position; The blades H are normally urged to the closed position by a spring 2-5 connected to the operating arms 2 3 upon relief of --pressure from the cylinder +9 by deenergization of the valve'windingfl" The engine water -o"t1et manifold 21 is .connected by pi'pe connection 29, including an auto matic'temperature responsive "control mechanism, shown generally at 31 ,to the inlet-of the radiator H. The outlet of thera-diator I I 'is shown connected by a pipe 32 and connections to a storage tank 33 having a fill pipe B l and an engine oil cooler '35 attached thereto and supported on the underframe 3 in the engine compartment by by means of legs 3-1. The engine P5 is provided with a coolant pump "39 driven thereby. The inlet of the pump is'connected by pipe connections-H to the engine oil cooler 5'5 and draws coolant therefrom and discharges thecoolant undei pressure to the engine inlet-coolant manifold 43 to cause circulationof cool-ant through the engine and radiator. a 1

The fan 13 and a grooved fan pulley-45 -is secured on a shaft 41 'rotatalole in a ran shroud ll! which is supported in the upper compartment of the hood 1. The fan :pulley t5 is-eonnected by means of 'V belts '51 to a grooved driven pulley member 53 of an air pressure engaged clutch member, indicated generally at 54 in Figures 1 and 3; on the 'errd-ofan engined-liven shaft 55 tor driving the fan 1 3. An air eompressor indicated generally-at -56 in-Figure -1, is shown mounted on the underf-rame 8 and is driven directly by the shaft-55. Y a

The air pressure engaged clutch mechanism 54 comprises the previously mentioned driven pulley member 53 which isrotatablymounted on the end of the shaft 55, -a dri-mng drum 5'! Within the pulleyand secured to the shaft '55 and an annular flexible pneumatic tireor gland 58 positioned between the driving drum 51 and :driven pulley 5'3 and secured toaflange $1 attached'to-the driven pulley memberQ A circular cover 63 is also secured to the outerface of the driven pulley 5'5 and is provided with a central air pressure openin 64 communicating with a radialpassage 5-5 therein and is connected to the interior of the gland or tire "59 by a tube 61. As best shown in Figure 1 an electromagnetic clutch-control valve 6 9 is connected by means of a flexible tube 'M to the stationary element :oi'a conventional rotary air pressure seal, indicated generally at E3, the rotary member'of which is connected tothe central air opening 64 of 'theclutchoover (it. With this arrangement when the electromagnetic clutch control valve -69 is energized air pressure is applied through the rotary seal 13 to the interior clutch gland or tire 59 secured to thecliitch driven pulley 53 to cause distension and frictional engagement of the tire with the clutch driving drum 51 for rotation therewith. The belts 5I from the clutch driven pulley 53 to the fan pulley 45 accordingly cause rotation of the radiator cooling fan I3 and circulation of air from the cooling air inlet opening 5 in the end of the hood I, through the radiator II and out through the upper air outlet opening 9 of the hood.

Suitable air pressure connections are provided from the locomotive air reservoir, ,not shown, supplied with air pressure from the compressor 56 to the shutter and clutch control electromagnetic valves 2I and 69. The electrical control connections between the shutter and clutch control valves and the automatic temperature responsive mechanism shown generally at 3I in the engine coolant outlet manifold connection 21 are shown schematically in detail in Figure 2 and will now be described. The automatic temperature responsive mechanism 3| comprises a thermal element 15 having one end 11 anchored and a stepped contact bar I secured to and movable successively into contact with adjacent stationary contacts IOI, I02, I03, I04, I and I06, certain ones of which are electrically connected by means of relays shown generally at I01-I08 with thewindings 2I' and 69' of the shutter and clutch control valves 2| and 69, respectively, to control energization and deenergization and opening of these valves in proper sequence for an increase and a decrease in engine temperature. The valves '2I and 69 are of conventional form, each having an exhaust port open to atmosphere when the windings are deenergized to vent the shutter cylinder I9 and clutch tire to atmosphere to cause closure of the shutters I1 and disengagement of the fan clutch 54.

The positive terminal of the locomotive battery I09 is connected to the contact IOI by a positive conductor H0 and the negative terminal is connected by a negative return conductor III and branch conductors leading therefrom to one side of the windings of each of relays I0'II08 and to one side of each of the control valve windings 2I69'. The other side of the winding of the relay I01 is connected by conductors H2 and H3 to the upper right-hand stationary contact of the relay I01 and also to the contact I04. The lower right-hand stationary contact of the relay I01 is connected by a conductor II4 to the other side of the shutter valve winding 2I'. The left-hand upper and lower stationary contacts of the relay I01 are connected byconductors II6-I H to the contact I03. The stepped contactor bar I00 is connected by a flexible conductor H8 and a conductor II9 to the left-hand upper and lower stationary contacts of the relay I08. The upper right-hand stationary contact of the relay I08 is connected to the contact I06 and to the other side of the winding of the relay I08 by conductors I20I 2 I. The lower right-hand stationary contact of the relay I08 is connected by a conductor I22 to the other side of the winding 69 of the clutch control valve. As shown, each of the relays I 01-408 has an armature provided with upper and lower contacts normally positioned out of contact with the upper and lower stationary relay contacts when the winding is deenergized. Energization of either relay winding causes the armature to move from the normal out of contact position as shown into contact with both the upper and lower pairs of stationary relay contacts.

With the temperature of the coolant in the engine outlet manifold 21 below the normal range of operating temperature the thermally expansible element 15 and stepped contact I00 operated thereby are in the position shown. Upon an increase in the temperature of the engine coolant to the minimum value in the range for efiicient engine operation, the stepped contact bar I00 is moved by expansion of the thermal element into contact with the stationary contact IOI so that the contacts I00-IOI are connected to the positive battery conductor. A higher temperature in the operating range causes the thermal element to move the stepped contact bar successively into contact with the stationary contact I02, I03 and I04. Contact I02 is not used but upon bridging of the contacts I03I04 by the contact bar I00 a circuit is established through the contacts I00-I03I04 to the winding of the relay I01 through conductors H0, I13, H2 and I II to cause bridging of the stationary relay contacts by the armature contacts. Bridging of the lower pair of contacts completes an energizing circuit through the winding 2I' of the shutter control valve through conductor IIO, contacts I00-I03 and conductors H1, H4 and III to cause opening of this valve to allow air pressure to enter the shutter cylinder I9 causing movement of the piston and rod therein to open the shutters I'I against the action of the spring 25 so that outside air may enter the air inlet opening 5 of the hood I. Bridging of the upper pair of contacts of the relay I01 establishes a holding energizing circuit to the winding of the shutter valve winding 2| through contacts I00-403 and conductors IIO, Ill, H6, H3, H2 and III. Ifthe load and temperature of the engine increases further to the upper portion of the operating range the thermal element 15 expands further and successively'moves the stepped contact I 00 into contact with the stationary contacts I 05 and I06. Contact I05 is not used but upon contact between the contacts I00 and I06 an energizing circuit is established therethrough and through the conductors H0 and I2I the winding of the relay I08 and conductor III to cause bridging of the stationary contacts of the relay I 08 by the armature contacts. Bridging oi the lower contacts of the relay I08 establishes an energizing circuit through the conductors H0, H8 and I22, the winding 69 of the clutch control valve 69 and return conductor I I I to cause opening of the clutch control valve 69 and application of air pressure to the clutch tire 59 through the rotary seal 13 to cause engagement thereof and opera- I tion of the radiator fan I3. Bridging of the upper contacts of the relay I08 establishes a holding energizing circuit through conductors H0, H8, H9, I20, I2I and'lII to the winding of the relay I08. The fan is capable of providing sufiicient circulation of cooling air through the radiator II for maximum values of ambient temperature, engine speed and load conditions and direction of locomotive operation and wind.

Upon a reduction in engine coolant temperature to below the operating range the thermal element 15 contracts and moves the stepped contact I00 out of contact with the stationary contacts I06, I04, I03, I02 and IOI successively. When the stepped contact I0!) is moved out of contact with the contact I03 the holdin energizing circuit comprising conductors H0, H1, H6, II3, H2 and III to the-winding of the relay I01 is broken causing opening of the relay contacts and deenergization of the winding 2I' of the shutter controlvalve 2 to cause venting oi the operating range and contact is moved out of contact with stationary contact l0! and the holding energizing circuit of the relay winding Hi8 comprising conductors H0, H8, H9, I20 and II I is broken causing opening of the relay contacts and deenergization of the winding 69 of the clutch control valve 69 to cause venting of the clutch tire 59 and disengagement of the fan clutch 54 and shut down of the fan l3.

It will be evident from the above description that upon increase in the temperature of the engine coolant to the upper portion of the operating range the shutters I! in the cooling air inlet opening are opened followed by operation of the radiator cooling fan I3 and upon a decrease in temperature to the lower portion of the operating range the shutters are closed followed by shut down of the fan. This overlapping reversed operating sequence prevents under and over cooling of the engine and thereby provides eflicient engine operation for wide variations of ambient temperature, direction and speed of winds and locomotive operation, and speed and output of the engine encountered in locomotive service.

I claim:

1. In a cooling system, an engine, a coolant radiator therefor, a radiator cooling fan, a clutch between said engine and said fan, shutters for controlling circulation of air through said radiator, an engine coolant temperature responsive device, control means for said clutch and said shutters connected to said device for sequential operation thereby whereby said shutters are opened prior to engagement of said clutch of said fan upon warm-up of said engine and said shutters are closed prior to disengagement of said clutch upon a decrease in said engine temperature.

2. In a cooling system, an engine, a coolant radiator therefor, a radiator cooling fan, a clutch between said engine and said fan, shutters for controlling flow of air through said radiator by convection and by action of said fan and combined shutter and clutch control means including engine coolant responsive means and relays having holding in means for causing overlapping reversed sequential operation of said shutters and said fan whereby said shutters are opened prior to operation of said fan by said engine at successively higher values of engine coolant temperature and said fan is shut down after closure of said shutters at successive lower Values of engine coolant temperature.

3. In a cooling system, an engine, a coolant radiator therefor, an engine driven coolant pump for circulating coolant through said engine and said radiator, means for controlling the flow of cooling air through said radiator, said means including a radiator cooling fan and shutters for permitting or preventing flow of air through said radiator, fan driving means including a clutch between said engine and said fan and combined shutter and clutch control means comprising relay means including holding means and engine coolant responsive control means whereby upon successively higher values of coolant temperature the shutters are opened prior to operation of the fan and atsucces'sively lower values of temperature the shutters are closed prior to shut down of the fan.

4. In a cooling system for an engine having a. coolant circulating pump, a coolant radiator and a radiator cooling fan, a pneumatic clutch between said engine and said fan, pneumatically operated shutters for permitting or preventing air flow through said radiator and combined control mechanism for causing overlapping reversed sequential operation of said shutters and said clutch, said mechanism including electropneumatic shutter and clutch control means, control relays including energizin holding means and engine coolant temperature responsive switching means for controlling said relays whereby said shutters are opened at one temperature and closed at a lower temperature and said fan clutch is engaged at a higher temperature than that causing the opening of said shutters and disengaged at a lower temperature than that causing the closure of said shutters.

THOMAS B. DILWOR'IH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,481,306 Stuart Jan 22, 1924 1,481,307 Stuart Jan. 22, 1924 1,837,564 McCaleb Dec. 22, 1931 2,336,840 Brehob Dec. 14, 1943 

